1. Field of the Invention
The disclosure relates to aback light module and a displaying apparatus, and especially relates to a back light module having a mount and using a light guiding plate to provide back light, and to a displaying apparatus with the back light module.
2. Description of the Prior Art
Common LCDs generally use a back light module with edge-lit LEDs to provide back light to a liquid crystal panel thereof. When the liquid crystal panel becomes bigger in size, the lighting units of the back light module need to operate at a higher power for maintaining the same illumination to the liquid crystal panel. Furthermore, the lighting units also need to be disposed as closer to the light guiding plate as possible, so that most light emitted by the lighting units can enter the light guiding plate. However, in principle, higher lighting power causes more generation of heat. In the back light module, with being close to the lighting units, the temperature becomes higher, so when being excessively close to or contacting the lighting units, the light guiding plate is very probably deformed or damaged due to a heat impact, leading to an uneven distribution of the back light provided by the light guiding plate. Additionally, the LCDs are usually mounted vertically. If the lighting units are disposed lower relative to the light guiding plate, the light guiding plate may move downward under its weight leading to an occurrence of the above issue of being excessively close to or contacting the lighting units.
In addition, the back light module is usually provided with an optical film sheet disposed on the light emitting surface of the light guiding plate, for modifying the property of the light out of the light emitting surface. In general, the optical film sheet is much thinner than the light guiding plate, so when the LCD is used vertically, the optical film sheet probably bends due to incapability of supporting its weight, unless sticking on the light guiding plate. This phenomenon also induces an uneven distribution of the back light provided by the light guiding plate. Moreover, the above issue will get worse with the increasing size of the liquid crystal panel.